The gambin model provides a superior fit to species abundance distributions with a single free parameter : evidence, implementation and interpretation

The species abundance distribution (SAD) has been a central focus of community ecology for over fifty years, and is currently the subject of widespread renewed interest. The gambin model has recently been proposed as a model that provides a superior fit to commonly preferred SAD models. It has also been argued that the model's single parameter (α) presents a potentially informative ecological diversity metric, because it summarises the shape of the SAD in a single number. Despite this potential, few empirical tests of the model have been undertaken, perhaps because the necessary methods and software for fitting the model have not existed. Here, we derive a maximum likelihood method to fit the model, and use it to undertake a comprehensive comparative analysis of the fit of the gambin model. The functions and computational code to fit the model are incorporated in a newly developed free-to-download R package (gambin). We test the gambin model using a variety of datasets and compare the fit of the gambin model to fits obtained using the Poisson lognormal, logseries and zero-sum multinomial distributions. We found that gambin almost universally provided a better fit to the data and that the fit was consistent for a variety of sample grain sizes. We demonstrate how α can be used to differentiate intelligibly between community structures of Azorean arthropods sampled in different land use types. We conclude that gambin presents a flexible model capable of fitting a wide variety of observed SAD data, while providing a useful index of SAD form in its single fitted parameter. As such, gambin has wide potential applicability in the study of SADs, and ecology more generally.

A satisfação dos trabalhadores com as práticas de gestão de recursos humanos: o caso de uma Instituição do Ensino Superior Público em Portugal

Este estudo tem como objetivos: (1) conhecer as práticas desenvolvidas numa organização do Ensino Superior Público Português; (2) conhecer a tipologia das práticas de GRH de cariz tradicional e de cariz estratégico; (3) perceber em que medida as práticas de GRH estão relacionadas com a área de qualificação dos responsáveis do departamento de RH; (4) averiguar o grau de satisfação que os trabalhadores sentem com as Práticas de Gestão de Recursos Humanos desenvolvidas e a sua relação com a área de qualificação dos responsáveis do departamento de RH. Foi utilizada uma metodologia mista, que possibilita ampliar a obtenção de resultados em abordagens investigativas, proporcionando ganhos relevantes para a pesquisa. É realizado um primeiro estudo exploratório, que utiliza uma metodologia mista quantitativa e qualitativa, com recurso a uma entrevista semiestruturada e inquérito realizados aos responsáveis de RH, e que tem como objetivos identificar e caracterizar as Práticas de GRH vigentes na Organização e, consequentemente, averiguar se se aproximam das designadas na literatura, assim como averiguar o grau de intervenção do DRH no desenvolvimento das PGRH e caraterizar o perfil do responsável de RH na Organização, averiguando se a área de formação de RH influencia as Práticas de GRH desenvolvidas. No segundo estudo, recorremos a uma metodologia quantitativa com recurso ao inquérito por questionário, aplicado aos trabalhadores que exercem funções a tempo integral, para averiguar o grau de satisfação dos trabalhadores em relação às Práticas de Gestão de Recursos Humanos. Na compilação dos dois estudos foi nosso objetivo obter respostas às questões que orientaram a nossa investigação. Na parte final da dissertação são discutidos os principais resultados obtidos e apresentadas as conclusões do estudo aqui levado a cabo. Os resultados sugerem que: 1) as PGRH existentes são essencialmente de cariz tradicional, em especial a gestão administrativa; 2) as PGRH predominantes são: o Planeamento de Recursos Humanos, a Análise e Descrição de Funções, o Recrutamento e Seleção, a Formação e Desenvolvimento, a Gestão Administrativa, a Comunicação e a Partilha de Informação, Ética e Deontologia e o Estatuto Disciplinar; 3) existe pouco recurso ao outsourcing para as PGRH; 4) o grau de intervenção DRH baseia-se em atividades de cariz mais administrativo; 5) as práticas tradicionais de RH são aquelas que requerem mais tempo ao DRH; 6) não existe relação entre o tipo de PGRH e a área de qualificação do responsável do DRH; 7) as PGRH são realizadas seguindo essencialmente as normas legais e regras rígidas da GRH na AP; 8) algumas PGRH não são entendidas em contexto da AP, como importantes pelos gestores, embora já sejam desenvolvidos alguns procedimentos dessas práticas; 9) a PGRH da formação e desenvolvimento não é corretamente desenvolvida e não dá cumprimento ao estipulado na lei; 10) a gestão de carreiras e o sistema de compensação e recompensas são entendidas como inexistentes, porque não existem promoções e progressões desde 2005; 11) a avaliação do desempenho é um sistema burocrático e ritualista com fins de promoção e compensação, sem efeitos práticos no momento atual, e que causa insatisfação e o sentimento de injustiça; 12) existem problemas de comunicação quanto a partilha e uniformização de procedimentos entre UO; 13) a satisfação dos trabalhadores é maior com as PGRH de tipo tradicional, nomeadamente na gestão administrativa, recrutamento e seleção, análise e descrição de funções, acolhimento, integração e socialização 14) a satisfação é menor na gestão de carreiras, no sistema de compensação e recompensas e na avaliação do desempenho; 15) quanto a relação entre o grau de satisfação e as características sócio demográficas e profissionais dos inquiridos, os casos com significância mostram que os trabalhadores com 10 ou mais anos de antiguidade tendem a sentir mais satisfação com as práticas em GRH; 16) existe mais satisfação dos trabalhadores das UO onde o responsável de DRH possui formação na área de RH.

Effects of dual-task training on balance and executive functions in Parkinson's disease: A pilot study

The aim of this study was to analyze the efficacy of cognitive-motor dual-task training compared with single-task training on balance and executive functions in individuals with Parkinson's disease. Fifteen subjects, aged between 39 and 75 years old, were randomly assigned to the dual-task training group (n = 8) and single-task training group (n = 7). The training was run twice a week for 6 weeks. The single-task group received balance training and the dual-task group performed cognitive tasks simultaneously with the balance training. There were no significant differences between the two groups at baseline. After the intervention, the results for mediolateral sway with eyes closed were significantly better for the dual-task group and anteroposterior sway with eyes closed was significantly better for the single-task group. The results suggest superior outcomes for the dual-task training compared to the single-task training for static postural control, except in anteroposterior sway with eyes closed.

Development of human central nervous system 3D in vitro models for preclinical research

Neurological disorders are a major concern in modern societies, with increasing prevalence mainly related with the higher life expectancy. Most of the current available therapeutic options can only control and ameliorate the patients’ symptoms, often be-coming refractory over time. Therapeutic breakthroughs and advances have been hampered by the lack of accurate central nervous system (CNS) models. The develop-ment of these models allows the study of the disease onset/progression mechanisms and the preclinical evaluation of novel therapeutics. This has traditionally relied on genetically engineered animal models that often diverge considerably from the human phenotype (developmentally, anatomically and physiologically) and 2D in vitro cell models, which fail to recapitulate the characteristics of the target tissue (cell-cell and cell-matrix interactions, cell polarity). The in vitro recapitulation of CNS phenotypic and functional features requires the implementation of advanced culture strategies that enable to mimic the in vivo struc-tural and molecular complexity. Models based on differentiation of human neural stem cells (hNSC) in 3D cultures have great potential as complementary tools in preclinical research, bridging the gap between human clinical studies and animal models. This thesis aimed at the development of novel human 3D in vitro CNS models by integrat-ing agitation-based culture systems and a wide array of characterization tools. Neural differentiation of hNSC as 3D neurospheres was explored in Chapter 2. Here, it was demonstrated that human midbrain-derived neural progenitor cells from fetal origin (hmNPC) can generate complex tissue-like structures containing functional dopaminergic neurons, as well as astrocytes and oligodendrocytes. Chapter 3 focused on the development of cellular characterization assays for cell aggregates based on light-sheet fluorescence imaging systems, which resulted in increased spatial resolu-tion both for fixed samples or live imaging. The applicability of the developed human 3D cell model for preclinical research was explored in Chapter 4, evaluating the poten-tial of a viral vector candidate for gene therapy. The efficacy and safety of helper-dependent CAV-2 (hd-CAV-2) for gene delivery in human neurons was evaluated, demonstrating increased neuronal tropism, efficient transgene expression and minimal toxicity. The potential of human 3D in vitro CNS models to mimic brain functions was further addressed in Chapter 5. Exploring the use of 13C-labeled substrates and Nucle-ar Magnetic Resonance (NMR) spectroscopy tools, neural metabolic signatures were evaluated showing lineage-specific metabolic specialization and establishment of neu-ron-astrocytic shuttles upon differentiation. Chapter 6 focused on transferring the knowledge and strategies described in the previous chapters for the implementation of a scalable and robust process for the 3D differentiation of hNSC derived from human induced pluripotent stem cells (hiPSC). Here, software-controlled perfusion stirred-tank bioreactors were used as technological system to sustain cell aggregation and dif-ferentiation. The work developed in this thesis provides practical and versatile new in vitro ap-proaches to model the human brain. Furthermore, the culture strategies described herein can be further extended to other sources of neural phenotypes, including pa-tient-derived hiPSC. The combination of this 3D culture strategy with the implemented characterization methods represents a powerful complementary tool applicable in the drug discovery, toxicology and disease modeling.

Dispositivo de avaliação externa ao ensino superior: um estudo exploratório sobre acreditação à Universidade Nacional Timor Lorosa'e, 2008 – 2013

Dissertação de mestrado em Ciências da Educação (área de especialização em Avaliação)

SI2ME: um serviço de informação para o trabalho no binómio monitorização-melhoria, no setor educativo não superior em Portugal

Tese de Doutoramento em Tecnologias e Sistemas de Informação.

Transnational study of roles/functions and associated ICT competencies for Higher Education teachers

Aquest estudi forma part del projecte eLene-TLC1 Virtual Campus (2007-2008) recolzat pel programa eLearning de la Comissió Europea. L'objectiu d'aquest projecte és que els professors i els estudiants facin el millor ús possible de les TIC en l'educació superior, preparant als professors per als estudiants de la generació xarxa, permetent als estudiants a la transferència de coneixements i pràctiques de la vida quotidiana per al seu aprenentatge i estimular tant la integració plena de pràctiques innovadores d'ensenyament i d'aprenentatge possibilitades per un entorn tecnològic en constant evolució. Per tal de cobrir part d'aquest objectiu general, es va concebre un estudi per examinar les competències en TIC professors d'Educació Superior en entorns d'aprenentatge en línia.

Hilbert space on probability density functions with Aitchison geometry

Compositional data analysis motivated the introduction of a complete Euclidean structure in the simplex of D parts. This was based on the early work of J. Aitchison (1986) and completed recently when Aitchinson distance in the simplex was associated with an inner product and orthonormal bases were identified (Aitchison and others, 2002; Egozcue and others, 2003). A partition of the support of a random variable generates a composition by assigning the probability of each interval to a part of the composition. One can imagine that the partition can be refined and the probability density would represent a kind of continuous composition of probabilities in a simplex of infinitely many parts. This intuitive idea would lead to a Hilbert-space of probability densitiesby generalizing the Aitchison geometry for compositions in the simplex into the set probability densities

Modulation of the Endocannabinoids N-Arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) on Executive Functions in Humans.

Animal studies point to an implication of the endocannabinoid system on executive functions. In humans, several studies have suggested an association between acute or chronic use of exogenous cannabinoids (Δ9-tetrahydrocannabinol) and executive impairments. However, to date, no published reports establish the relationship between endocannabinoids, as biomarkers of the cannabinoid neurotransmission system, and executive functioning in humans. The aim of the present study was to explore the association between circulating levels of plasma endocannabinoids N-arachidonoylethanolamine (AEA) and 2-Arachidonoylglycerol (2-AG) and executive functions (decision making, response inhibition and cognitive flexibility) in healthy subjects. One hundred and fifty seven subjects were included and assessed with the Wisconsin Card Sorting Test; Stroop Color and Word Test; and Iowa Gambling Task. All participants were female, aged between 18 and 60 years and spoke Spanish as their first language. Results showed a negative correlation between 2-AG and cognitive flexibility performance (r = -.37; p<.05). A positive correlation was found between AEA concentrations and both cognitive flexibility (r = .59; p<.05) and decision making performance (r = .23; P<.05). There was no significant correlation between either 2-AG (r = -.17) or AEA (r = -.08) concentrations and inhibition response. These results show, in humans, a relevant modulation of the endocannabinoid system on prefrontal-dependent cognitive functioning. The present study might have significant implications for the underlying executive alterations described in some psychiatric disorders currently associated with endocannabinoids deregulation (namely drug abuse/dependence, depression, obesity and eating disorders). Understanding the neurobiology of their dysexecutive profile might certainly contribute to the development of new treatments and pharmacological approaches.

Cerebrospinal fluid biomarkers of central nervous system dysfunction in HIV-infected patients

Background :¦In addition to opportunistic infections of the central nervous system (CNS), which are due to immunosuppression related to HIV, the latter virus, itself, can cause neuropathological abnormalities which are located mainly in the basal ganglia and are characterized by microglial giant cells, reactive astrocytosis and perivascular monocytes. This HIV encephalopathy is characterized, clinically, by psycho-motor slowing, memory loss, difficulties in complex tasks requiring executive functions, as well as motor disorders .These cognitive deficits are grouped under the acronym of HIV-associated neurocognitive disorders (HAND). In fact, HANDs are subdivided in three groups in accordance with the severity of the cognitive impairment: Asymptomatic Neurocognitive Impairment (ANI), Mild/moderate Neurocognitive Disorders (MND) and HIV Associated Dementia (HAD).¦While the incidence of HAD has significantly decreased in the era of combined antiretrobiral therapy (cART), the prevalence of milder forms of HIV-associated neurocognitive disorders HAND seem to have increased. There are many potential reasons to explain this state of facts.¦An important question is to understand how soon the brain may be affected by HIV. Since performing a biopsy in these patients is not an issue, the study of the CSF represents the best available way to look at putative biomarkers of inflammation/neurodegeneration in the CNS. Here, we wanted to examined the putative usefulness of different biomarkers as early indicators of anti-retroviral failure at the level of the CNS. We chose to study the CSF levels of:¦Amyloid-β 1-42 (Aβ42), Tau total (tTau), phosphorylated Tau (pTau), Neopterin and S100-β.¦Indeed, these molecules are representative biomarkers of the major cells of the CNS, i.e. neurons,¦macrophages/microglia and astrocytes.¦To examine how sensitive were these CSF biomarkers to indicate CNS insults caused by HIV, we proposed to take advantage of the MOST (Monotherapy Switzerland/Thailand study) study, recently published in AIDS. Thus, we collaborated with Prof. Pietro Vernazza in St-Gall. In MOST study, monotherapy (MT) consisting in ritonavir-boosted lopinavir (LPV/r) was compared to continuous conventional antiretroviral therapy including several molecules, hereafter referred as CT¦Methods :We tested 61 cerebrospinal fluid (CSF) samples from 52 patients enrolled in MOST, including 34 CSF samples of CT and 27 of MT (mean duration on MT: 47+20 weeks) in patients who maintained full VL suppression in blood (<50cps/ml). Using enzyme-linked immunosorbent assay (ELISA), we determined the CSF concentration of S100-beta (astrocytosis), neopterin (microglia, inflammation), total Tau (tTau), phosphorylated Tau (pTau), and amyloid-beta 1-42 (Abeta), the latter three markers indicating neuronal damages. The CSF samples of 37 HIV-negative patients with Alzheimer dementia (AD) served as controls. Results are expressed in pg/ml and reported as median ± interquartile range. Mann Whitney-U test was used to compare the results of a given biomarker between two groups and the Fisher test to compare frequencies.¦Results: We found a higher concentration of S100-beta (570±1132) and neopterin (2.5±2.9) in the CSF of MT versus CT (0±532, p=0.002 and 1.2±2.5, p=0.058, respectively). A cutoff of 940 pg/ml for S100-beta allowed to discriminate MT (11 above versus 16 below) from CT (1 vs 33, p=0.0003). At a lesser extent, a cutoff of 11 pg/ml for neopterin separated MT (4 above versus 23) from CT (0 vs 34, p=0.034) (Figure).¦In AD, tTau was higher (270±414) and Abeta lower (234±328) than in CT (150±153, p=0.0078, and 466±489, p=0.007, respectively). Such as for CT, Abeta was lower in AD than in MT (390±412, p=0.01). However, contrasting with CT, the levels of tTau were not different between AD and MT (199±177, p=0.11). S100b (173±214; p=0.0006) and neopterin (1.1±0.9; p=0.0014) were lower in AD than MT.¦Conclusions: Despite full VL-suppression in blood, HIV monotherapy is sufficient to trigger inflammation and, especially, astrocytosis. CSF markers of patients on CT have the same profile as reported for healthy subjects, suggesting that CT permits a good control of HIV in the brain. Finally, the levels of tTau, which are relatively similar between AD and MT patients, suggest that neurons are damaged during monotherapy.

Modulation of Higher-Order Olfaction Components on Executive Functions in Humans.

The prefrontal (PFC) and orbitofrontal cortex (OFC) appear to be associated with both executive functions and olfaction. However, there is little data relating olfactory processing and executive functions in humans. The present study aimed at exploring the role of olfaction on executive functioning, making a distinction between primary and more cognitive aspects of olfaction. Three executive tasks of similar difficulty were used. One was used to assess hot executive functions (Iowa Gambling Task-IGT), and two as a measure of cold executive functioning (Stroop Colour and Word Test-SCWT and Wisconsin Card Sorting Test-WCST). Sixty two healthy participants were included: 31 with normosmia and 31 with hyposmia. Olfactory abilities were assessed using the ''Sniffin' Sticks'' test and the olfactory threshold, odour discrimination and odour identification measures were obtained. All participants were female, aged between 18 and 60. Results showed that participants with hyposmia displayed worse performance in decision making (IGT; Cohen's-d = 0.91) and cognitive flexibility (WCST; Cohen's-d between 0.54 and 0.68) compared to those with normosmia. Multiple regression adjusted by the covariates participants' age and education level showed a positive association between odour identification and the cognitive inhibition response (SCWT-interference; Beta = 0.29; p = .034). The odour discrimination capacity was not a predictor of the cognitive executive performance. Our results suggest that both hot and cold executive functions seem to be associated with higher-order olfactory functioning in humans. These results robustly support the hypothesis that olfaction and executive measures have a common neural substrate in PFC and OFC, and suggest that olfaction might be a reliable cognitive marker in psychiatric and neurologic disorders.

Concepções, Práxis e Tendências de Desenvolvimento Curricular no Ensino Superior Público em Cabo Verde: um Estudo de Caso Sobre a Universidade de Cabo Verde

A tese enquadra-se nas discussões sobre as concepções do currículo, como problemática central nos processos de educação e formação, e o papel da Universidade ao longo dos tempos, mormente nos contextos actuais da globalização, conferindo especial relevo às concepções, práxis e tendências que caracterizam a experiência de desenvolvimento curricular na Universidade de Cabo Verde (Uni-CV), desde a sua criação, em Novembro de 2006, no seguimento de um percurso de quase três décadas do ensino superior público cabo-verdiano Com o enquadramento teórico da problemática da investigação faz-se uma ampla cartografia da literatura relevante no campo científico dos estudos curriculares, numa abordagem que patenteia a diversidade de conceptualizações do currículo e do desenvolvimento curricular, os principais traços característicos das teorias curriculares que se têm sucedido e ou que rivalizam na busca de hegemonia no sector da educação, bem como as políticas educativas e curriculares que vêm sendo concebidas e realizadas à escala global, dispensando atenção particular às dimensões instituinte e instituída do processo curricular. Ainda que fortemente condicionado pelas concepções e políticas de globalização da educação, a tendência para a uniformização educativa e curricular não constitui uma inevitabilidade, demonstrando-se, pelo contrário, que o processo de desenvolvimento curricular deixa espaços de apropriação e inovação ao nível das instituições educativas, atendendo à diversidade de contextos, expectativas e perspectivas inerentes à dinâmica da realização do currículo. Ainda no plano teórico, ao analisar-se a evolução do conceito ou ideia de Universidade, desde a sua génese até aos tempos actuais, coloca-se em relevo a natureza específica da instituição no âmbito do ensino superior, patenteando o modo como, nos diferentes contextos, a mesma tem procurado afirmar a centralidade do conhecimento e do currículo no cumprimento da sua missão, a despeito de factores e condicionalismos diversos, de entre os quais releva o tipo de relacionamento predominante entre a Universidade, o Estado e o mercado, no âmbito do qual se deve entender a complexidade da crise institucional, na triplicidade das suas manifestações (crise de legitimidade, de hegemonia e de identidade) que atravessa a academia, com reflexos ao nível das tendências para o condicionamento da autonomia, missão e funções da academia, assim como da própria natureza do conhecimento universitário. Na procura de saídas para a crise, que é global e, como tal, se reflecte nas universidades do continente africano, em que se insere Cabo Verde, a Universidade é desafiada a afirmar a sua especificidade institucional, enquanto promotora da alta cultura e da capacidade de pensamento de longo prazo, conciliando, deste modo, as suas funções essenciais ou simbólicas com as que se prendem com a satisfação das necessidades imediatas ou de curto prazo da economia e do mercado. Com base nos pertinentes subsídios teóricos, os estudos empíricos desenvolvem-se segundo a abordagem metodológica de estudo de caso, em que a análise documental e as técnicas de investigação qualitativa e quantitativa permitiram consolidar as evidências sobre: (i) os antecedentes da criação da Uni-CV, através do mapeamento do percurso académico e curricular dos diversos estabelecimentos públicos de ensino superior que precederam a universidade pública, legando a esta o seu património científico, tecnológico e logístico, com as inerentes potencialidades e limitações; (ii) o processo de institucionalização da Uni-CV, com a referencialização das opções estruturantes da organização e gestão da Universidade assim como da política educativa e curricular da Universidade; (iii) a experiência multifacetada de desenvolvimento curricular na novel instituição durante os cinco primeiros anos de funcionamento (2006-2011), correlacionando opções e práxis e evidenciando tendências da sua evolução. Da análise interpretativa dos estudos empíricos realizados, mediante a triangulação dos dados de arquivo e de perspectiva, resulta que a Uni-CV, não obstante as fragilidades persistentes no processo de seu desenvolvimento institucional, tem cumprido a sua missão de forma satisfatória, facto que fica a dever-se quer à adequação das opções, normas e directivas conformadoras da dimensão instituinte do processo curricular, quer ao esforço de realização das prescrições curriculares, sendo, todavia, evidentes os desafios a serem vencidos tendo em vista a consecução da almejada excelência académica, que os Estatutos propugnam, e que passa, nomeadamente, pela melhoria do nível da qualificação do seu corpo docente, pela implementação ou funcionamento efectivo de alguns dos órgãos da academia e pela afirmação da investigação científica como função incontornável para o desempenho cabal das funções de ensino e extensão. De entre as conclusões, sustenta-se que, no processo de integração de Cabo Verde nas redes internacionais de investigação e excelência científica e tecnológica, como, de resto, propugnam os Estatutos da Uni-CV, deve atender-se à especificidade deste pequeno país do Atlântico Médio, tendo em conta as suas fragilidades estruturais, pelo que se impõe algum distanciamento crítico em relação à incorporação de certas opções de política educativa e curricular que emanam de instâncias internacionais, independentemente do seu carácter inovador ou mesmo da sua possível consistência científica e técnica, comprovada em outros contextos.

Epithelial sodium channel/degenerin family of ion channels: a variety of functions for a shared structure.

The recently discovered epithelial sodium channel (ENaC)/degenerin (DEG) gene family encodes sodium channels involved in various cell functions in metazoans. Subfamilies found in invertebrates or mammals are functionally distinct. The degenerins in Caenorhabditis elegans participate in mechanotransduction in neuronal cells, FaNaC in snails is a ligand-gated channel activated by neuropeptides, and the Drosophila subfamily is expressed in gonads and neurons. In mammals, ENaC mediates Na+ transport in epithelia and is essential for sodium homeostasis. The ASIC genes encode proton-gated cation channels in both the central and peripheral nervous system that could be involved in pain transduction. This review summarizes the physiological roles of the different channels belonging to this family, their biophysical and pharmacological characteristics, and the emerging knowledge of their molecular structure. Although functionally different, the ENaC/DEG family members share functional domains that are involved in the control of channel activity and in the formation of the pore. The functional heterogeneity among the members of the ENaC/DEG channel family provides a unique opportunity to address the molecular basis of basic channel functions such as activation by ligands, mechanotransduction, ionic selectivity, or block by pharmacological ligands.

Emerging functions of myelin associated proteins during development neuronal plasticity and and neurpdegeneration.

Adult mammalian central nervous system (CNS) axons have a limited regrowth capacity following injury. Myelin-associated inhibitors (MAIs) limit axonal outgrowth and their blockage improves the regeneration of damaged fiber tracts. Three of these proteins, Nogo-A, MAG and OMgp, share two common neuronal receptors: NgR1, together with its co-receptors (p75(NTR), TROY and Lingo-1), and the recently described paired immunoglobulin-like receptor B (PirB). These proteins impair neuronal regeneration by limiting axonal sprouting. Some of the elements involved in the myelin inhibitory pathways may still be unknown, but the discovery that blocking both PirB and NgR1 activities leads to near-complete release from myelin inhibition, sheds light on one of the most competitive and intense fields of neuroregeneration study during in recent decades. In parallel with the identification and characterization of the roles and functions of these inhibitory molecules in axonal regeneration, data gathered in the field strongly suggest that most of these proteins have roles other than axonal growth inhibition. The discovery of a new group of interacting partners for myelin-associated receptors and ligands, as well as functional studies within or outside the CNS environment, highlights the potential new physiological roles for these proteins in processes such as development, neuronal homeostasis, plasticity and neurodegeneration.